Ice mass could make a watery mess

ANTARCTICA — An Antarctic ice sheet the size of Texas and Colorado combined is melting and could disappear in 7,000 years, possibly raising worldwide sea levels by as much as 16 feet.

Based on geologic measurements that date when rocks first become free of ice, researchers have found that the West Antarctic Ice Sheet started retreating about 10,000 years ago, said John O. Stone, first author of a study appearing Friday in the journal Science.

If the sheet does melt entirely, he said, the global sea level could rise by 16 feet, enough to drown some islands and coastal areas.